Friday, February 27, 2009

Dinan Muffler

So I waited and waited for a Dinan Muffler to come in to work because I knew my muffler was bad. Originally I had put a slightly used SuperSprint exhaust aside and some one at the shop sold it out from under me. Then when I couldn't wait any longer and my old muffler literally fell off, I put on a stock M3 muffler assy. 1 week later this shows up. Well, I have it now. I hope to get this on the car as soon as I get a chance. It's off of an E36, so I'll need to add a couple brackets to make it fit, like I did the stock M3 muffler.

Thursday, February 26, 2009

E36 M3 suspension

If you are considering swapping your 4 lug suspension for 5 lug, a few notes about using M3 suspension.

Front - You will need the complete front struts/springs froma 96-99 E36 M3 for the 5 lug swap. Also required are the front control arms and offset control arm busings.

Rear - I do not know of any way to use the rear E36 trailing arms. You cannot use the E36 M3 differential or the axles either. The M3 diff will not bolt to the E30 subframe, and has a CV input flange. E36 M3 axles only work with the M3 diff and M3 control arms, due to the large diameter spline where it goes into the wheel bearing.

Rear suspension needs to come from a 318ti or Z3. If you can find them, and have the cash, you can use the MZ3 rear control arm which are beefier and allow you to use the larger diameter M-tech brakes.

I have another post about doing the 5 lug conversion


What driveline do I use for the M50/S50 M52/S52 change over?

If you are using the ZF five speed that came in 328/528/M3 cars, you can use the E36 328i five speed driveline. Obviously, this driveline matches the 3 bolt flange at the back of the five speed tranmission and uses a rubber flex disc (guibo) to couple the driveline to the driveline. At the opposite end, the E36 328i five speed driveline is an exact match to your four bolt input flange on the E30 differential.

The one thing that will need to be changed when using the E36 328i five speed driveline is the center carrier bearing. You will need to install an E30 center carrier bearing on the E36 328i driveline.


I have recently had several people ask me what gear ratio differential I am running with my 2.8L M52. I have a S3.25 posi from a 1987 535is E28.Originally my 1986 325 came with a non-posi 2.93. Horrible! Spun the tires at every corner, even with the old 2.7L M20 engine. Even before the engine swap I changed the differential.

There are plenty of gear ratio choices and BMW's to get differentials from. The E28 and E24 diff's will work in a E30, as long as you change the rear cover and the output flanges. Gear Ratios are as follows:


2.79 and 2.93 are about the lowest gear ratios, which while great for the freeway and gas milage, makes for slow starts. You can go all the way to 4.27 which I believe came in the 91-93 318i convertables, but this makes first gear useless in a five speed car. Even the 4.10 which came in a lot of the 325i automatics and also in the S14 M3, make first gear pretty quick and limit top end speed. I have heard good things with the 3.73, very quick, gas milage isn't too bad either.

I believe the S3.25 is the perfect gear ratio, it is both quick off the line and has plenty of top end. I run at 2200rpm at 55mph while in 5th gear . I am getting about 18mpg in commute traffic and I drive with a pretty heavy foot.

All these diffs are available in posi and non posi. Make sure if you buy the posi (limited slip) that there is a "S" in front of the gear ratio. The "S" signifies posi (limited slip).

When changing the diff out, you can put a MZ3 rear diff cover on which adds and extra quart of fluid and has cooling fins that hang down in the slip stream below the car.

If you are doing a 5 lug change over, you can keep the E24/E28 output flanges if you use the 318ti axles. I think you also need the E24/E28 out put flanges for the MZ3 axles and trailing arms.

Important note: When replacing the diff, make sure it is aligned and completely pressed up against the subframe or the bolts will not go back in.